Find the 12th term of an arithmetic sequence given that its 5th term is 16 and 11th term is 43
Answer (1)
Answer:the 12th term is 47.5Step-by-step explanation:formula : an = a + (n−1)d5th term: a + 4d = 1611th term: a + 10d = 43(a+10d) - (a+4d) = 43 - 16 ⇒ 6d = 27 ⇒ d = 4.5 a+4(4.5)=16 ⇒ a+18=16 ⇒ a=−2a₁₂ = a+11d = −2+11(4.5) = −2+49.5 = 47.5
